Payload envelope db operations (#8717)

Adds support for payload envelopes in the db. This is the minimum we'll need to store and fetch payloads.


  


Co-Authored-By: Eitan Seri- Levi <eserilev@gmail.com>

beacon_node/beacon_chain/src/migrate.rs

@@ -773,6 +773,7 @@ impl<E: EthSpec, Hot: ItemStore<E>, Cold: ItemStore<E>> BackgroundMigrator<E, Ho
                     StoreOp::DeleteBlock(block_root),
                     StoreOp::DeleteExecutionPayload(block_root),
                     StoreOp::DeleteBlobs(block_root),
+                    StoreOp::DeletePayloadEnvelope(block_root),
                     StoreOp::DeleteSyncCommitteeBranch(block_root),
                 ]
             })